Patent GB-1248588-A (GB)
Title: Stabilizing system for a ground effect vehicle
Inventor: GIRAUD FRANCOIS LOUIS
IPC: B60V3/04
Filed: 1968-10-01
Abstract: 1,248,588. Air cushion vehicles; railway systems. SOC. DE L'AEROTRAIN. 1 Oct., 1968 [4 Oct., 1967; 26 June, 1968], No. 46469/68. Headings B7K and B7L. In a ground effect machine adapted to move along a track 10 (e.g. of inverted T-shape) first and second pressure fluid cushions (i.e. air) 11a, 11b exert opposing forces on the track 10, first and second cushion seals 14a, 14b of variable effectiveness peripherally confine the cushions, the arrangement being such that movement of the machine relative to the track causes one cushion to move towards its associated surface with a corresponding increase in pressure, and the other cushion to move away from its associated surface with a corresponding decrease in pressure, means sensitive to the pressure increase in the one cushion act with complementary means to further reduce the pressure in the other cushion and so cause an enhanced restoring force 29 to act on the vehicle. In one embodiment (Fig. 2) the seals 14a, 14b are flanges connected to hinges 40, which hinges also are connected to one end of a rod 17 pivotably mounted at 16, the whole forming a pressure sensitive system 13a or 13b. The rods 17 act as a spring, and have an associated arm 17a or 17b having a shoe 18 which forms a frictionally operated damping means. The hinge 40 also connects flange 14a or 14b with a respective control arm 21, which control arms are connected together through links 22 and a bellcrank 24. Thus if the vehicle is moved against the track under a force F the pressure in cushion 11a increases. Simultaneously cushion 11b moves away from the track and its pressure decreases. The pressure increase in cushion 11a causes pressure sensitive system 13a to move away from the track to increase the leakage gap. This consequently moves control arm 21 about its pivot 41 and through the links 22 the other control arm 21 is moved about its pivot 41 to move system 13b and hence cushion 11b still further from the track. This enables the machine to restabilize itself. Auxiliary plungers 64a, 64b are provided as insurance in event of damage to flanges 14a, 14b. The cushions 11a, 11b may be bounded by upper and lower flanges connected in the above manner. In an alternative embodiment (Fig. 9) the pressure adjusting means is pneumatic. The flanges 14a, 14b are respectively connected to hinged back-plates 31a, 31b, part of which plates 54a, 54b are connected to a flexible wall of chamber 51a, 51b. Cushion 11a is connected to chamber 51b and cushion 11b to chamber 15a. When cushion 11a is moved against its surface of track 10 the pressure increases in both cushion 11a and chamber 51b. Conversely pressure decreases in cushion 11b and chamber 51a. However, the flange 14a is moved to further increase the volume of chamber 51a via plate 54a. This in turn further reduces the pressure in cushion 11b and so restores equilibrium. In a further embodiment (Fig. 11, not shown) the cushions are formed by compressed air issuing from a port, the area of which is variably adjusted by a spring loaded valve operating in response to the pressure in an opposing cushion. In that embodiment the vehicle rides on track of trapezoidal crosssection. Also a plurality of cushions may be provided against each track surface. In such resilient diaphragm and bellows are provided with each flange operative to stabilize the vehicle only beyond a predetermined threshold to reduce exaggerated sensitivity.